Definition Of Virus For Class 8

Virus definition viruses are infectious agents that replicate inside the body of a host in biology viruses are microscopic entities that are able to replicate inside the cell of its host.

Definition of virus for class 8. A computer virus is a malicious software program loaded onto a user s computer without the user s knowledge and performs malicious actions. Virus attaches itself to files stored on floppy disks usbs email attachments and hard disks. A file containing a virus is called infected file. If what you are looking for is a simplified definition of virus suitable for explaining to an eighth grader here it is.

How to avoid spreading of micro organisms has been discussed. If this file is copied to a computer virus is also copied to the computer. The term computer virus was first formally defined by fred cohen in 1983 computer viruses never occur naturally. Virus classification is the process of naming viruses and placing them into a taxonomic system similar to the classification systems used for cellular organisms.

The name virus means venom or poisonous fluid given by louis pasteur. A vaccine is an inactivated form of bacteria or virus that is injected into the body to simulate an actual infection. Microorganisms class 8 science chapter 2 as per ncert book used in cbse and other schools. The virus which infects insects is known as insect virus also called the viral pathogen of insects.

Virus definition is any of a large group of submicroscopic infectious agents that are usually regarded as nonliving extremely complex molecules that typically contain a protein coat surrounding an rna or dna core of genetic material but no semipermeable membrane that are capable of growth and multiplication only in living cells and that cause various important diseases in humans animals. Once created and released however their diffusion is not directly under. Viruses are microscopic organisms that come alive only when inside a host organism that is they reproduce only inside anoth. They are always induced by people.

The lesson covers the complete explanation of class 8 chapter 2 microorganisms topics covered are introduction to micro organisms and microbiology different types of micro organisms useful and harmful micro organisms. Because the injected microorganisms are dead they don t cause a person to. The formal taxonomic classification of viruses is the. These viruses are considered as a powerful biocontrol agent in the landscape of modern agriculture.

Viruses are mainly classified by phenotypic characteristics such as morphology nucleic acid type mode of replication host organisms and the type of disease they cause.